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15 votes
15 votes
Part a is already complete, answer is (2p+12)/13 + (3p-8)i/13. need help with part b

Part a is already complete, answer is (2p+12)/13 + (3p-8)i/13. need help with part-example-1
User Saghachi
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1 Answer

12 votes
12 votes

We are given a complex number of the form:


w=(2p+12)/(13)+(3p-8)/(13)i

We are also given that arg(w) = π/4. With this information, we can calculate the value of p.

The argument of a complex number is defined as:


\tan w=(y)/(x)

Where y and x are the imaginary and real parts (respectively) of the complex number. Applying the formula:


\tan (\pi)/(4)=((3p-8)/(13))/((2p+12)/(13))

Since the tangent of π/4 is 1, the real and the imaginary parts happen to be equal, that is:


\begin{gathered} ((3p-8)/(13))/((2p+12)/(13))=1 \\ (3p-8)/(13)=(2p+12)/(13) \end{gathered}

Simplifying by 13:


\begin{gathered} 3p-8=2p+12 \\ \text{Simplifying:} \\ 3p-2p=12+8 \\ \text{Solving:} \\ p=20 \end{gathered}

Substituting into the complex number:

w = 3 + 3i

User Francois Nel
by
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